Simultaneously achieving ultrahigh loading and ultrasmall particle size of Pt/C catalysts

High-loading Pt/C catalysts play an important role in the fabrication of membrane electrode assemblies with thin catalytic layer, which enhance mass transport and maintain the balance of water and heat. Unfortunately, as the loading increases, the agglomeration and growth of Pt nanoparticles (NPs) occur, causing unsatisfactory performance. Here, we present an efficient method for preparing of highly dispersed and small-sized Pt/C catalysts with Pt loadings varying from 39.01 wt% to 66.48 wt% through the high-temperature shock technique. The high density and ultrafine (~2.5 nm) Pt NPs are successfully anchored onto Vulcan XC-72R carbon black without the use of additional capping agents or surfactants. The modified carbon supports enhance the affinity for Pt precursors, contributing to loading efficiencies of 95% or more, while also providing abundant sites for the nucleation and fixation of Pt NPs, thus preventing agglomeration. In the context of the hydrogen evolution reaction in acidic media, the as-synthesized high-loading Pt/C catalysts show remarkable activity and stability, outperforming the state-of-the-art commercial Pt/C. This is mainly because the combined effects of ultrasmall and uniform Pt NPs, optimized electronic structure of Pt site, superhydrophilicity and effective anchoring of Pt NPs. The polymer electrolyte membrane electrolyzer integrated with Pt60/OX72R and commercial IrO 2 reaches 1 A cm –2 at 1.77 V and operates stably for 120 hours with a negligible voltage decay. This new strategy is fast, scalable and cost-effective for large-scale production of metal-supported catalysts, especially for the high-loading ones.